Accurate proportioning of both is essential; determine pH of water supply, if above 6.0 adjustment is optional; achieve about pH of 5.0 to 5.4, plus approximately 146 ppm. of nitrogen for mature plants, plus same of phosphorus and potassium; many other details given; refer to F68-118+
More
The Orchid Doctor
Articles under the Heading
Citric Acid
Citric Acid
Comments
CITRIC ACID: Used to Lower Ph of Water
It is a good chelating substance and could be responsible for excellent growth of some orchids; also metabolite of living aerobic systems; most plants manufacture their own. F68-114